Many surgical procedures typically require large incisions be made to provide access to regions within the body. For instance, operating on or near the posterior regions of the heart is ordinarily performed using open-chest techniques. Such a procedure generally requires a gross thoracotomy or sternotomy, which are both highly invasive and attendant with a great deal of risks, such as ischemic damage to the heart, formation of emboli, etc. A thoracotomy typically involves creating an incision in the intercostal space between adjacent ribs while a sternotomy involves the “chest spreader” approach, which is generally the most invasive. Moreover, such an invasive procedure produces significant morbidity, increased mortality rates, and significantly increases recovery time for the patient.
Minimally invasive surgery is an alternative surgical procedure in which small incisions are made in the patient's body to provide access for various surgical devices for viewing and operating inside the patient. Laparoscopes are typically used for accessing and performing operations within the body through these small incisions using specially designed surgical instruments. These instruments generally have handles which are manipulatable from outside of the patient's body by the surgeon to control the operation of the instrument typically through an elongated tubular section which fits through a tube, introducer, or trocar device entering the patient's body.
However, even conventional laparoscopic procedures are limited in applicability in part because of a “straight-line” requirement in utilizing laparoscopic tools. This requirement makes accessing certain areas within the body extremely difficult, if not impracticable. Moreover, the lack of flexibility of these tools have made access to certain regions of the body difficult, forcing many surgeons to resort to open surgery rather than utilizing conventional minimally invasive procedures.
Flexible endoscopic devices are also available for use in minimally invasive surgical procedures in providing access to regions within the body. Flexible endoscopes are typically used for a variety of different diagnostic and interventional procedures, including colonoscopy, bronchoscopy, thoracoscopy, laparoscopy and video endoscopy. A flexible endoscope may typically include a fiberoptic imaging bundle or a miniature camera located at the instrument's tip, illumination fibers, one or two instrument channels that may also be used for insufflation or irrigation, air and water channels, and vacuum channels. However, considerable manipulation of the endoscope is often necessary to advance the device through the body, making use of conventional devices more difficult and time consuming and adding to the potential for complications.
Steerable flexible endoscopes have been devised to facilitate selection of the correct path through regions of the body. However, as the device is typically inserted farther into the body, it generally becomes more difficult to advance. Moreover, friction and slack in the endoscope typically builds up at each turn, making it more difficult to advance and withdraw the device. Another problem which may arise, for example, in colonoscopic procedures, is the formation of loops in the long and narrow tube of the colonoscope. Such loops may arise when the scope encounters an obstacle, gets stuck in a narrow passage, or takes on a shape that incorporates compound curves. Rather progressing, the scope forms loops within the patient. In an attempt to proceed in insertion of the colonoscope, for example, excess force may be exerted, damaging delicate tissue in the patient's body. The physician may proceed with the attempted insertion of the endoscope without realizing there is a problem.
Through a visual imaging device the user can observe images transmitted from the distal end of the endoscope. From these images and from knowledge of the path the endoscope has followed, the user can ordinarily determine the position of the endoscope. However, it is difficult to determine the endoscope position within a patient's body with any great degree of accuracy.
None of the instruments described above is flexible enough to address the wide range of requirements for surgical procedures performed internally to the patient's body. Furthermore, the instruments described lack the ability to rotate the distal tip about the longitudinal axis of the instrument while fully articulating the tip to any setting relative to the tubular section of the instrument. This lack of flexibility requires surgeons to manually rotate and move the instrument relative to the patient body to perform the procedure.